<template>
  <section class="todoapp">
    <!-- 除了驼峰, 还可以使用-转换链接 -->
    <TodoHeader @addTask="addTaskFn" :list="list"></TodoHeader>
    <TodoMain :list="showList" @del="delFn"></TodoMain>
    <TodoFooter
      @changeType="typeFn"
      :type="getSel"
      :len="showList.length"
      @clearTak="clearFn"
    ></TodoFooter>
  </section>
</template>

<script>
// 1.0 样式引入
import "./styles/base.css";
import "./styles/index.css";

import TodoHeader from "./components/TodoHeader";
import TodoMain from "./components/TodoMain";
import TodoFooter from "./components/TodoFooter";

export default {
  components: {
    TodoHeader,
    TodoMain,
    TodoFooter,
  },
  data() {
    return {
      list: JSON.parse(localStorage.getItem("todolist")) || [],
      getSel: "all",
    };
  },
  methods: {
    addTaskFn(task) {
      this.list.push({
        id: this.list.length ? this.list.at(-1) + 1 : 100,
        name: task,
        isDone: false,
      });
    },
    delFn(id) {
      this.list = this.list.filter((item) => item.id !== id);
    },
    typeFn(type){
      this.getSel=type
    },
    clearFn(){
      this.list=this.list.filter((item)=>!item.isDone)
    }
  },
  computed: {
    showList(){
      if(this.getSel==='yes'){
        return this.list.filter((item)=>item.isDone)
      }else if(this.getSel==='no'){
        return this.list.filter((item)=>!item.isDone)
      }else{
        return this.list
      }
    }
  },
  watch: {
    list:{
      deep:true,
      handler(){
        localStorage.setItem('todolist',JSON.stringify(this.list))
      }
    }
  }
};
</script>
